In the packaging of heavy products, for example home appliances including washers, dryers, refrigerators, and the like, a preferred procedure involves the use of spaced support posts extending between a bottom appliance supporting platform and a top cap with a surrounding protective sleeve of corrugated cardboard or plastic wrap.
Such support posts are normally formed of paperboard and adhesive, or other material, convolutely wound into a tubular configuration and transversely formed to the desired post configuration. Such tube formed support posts are considered particularly desirable in light of the substantial strength achieved and the economies derived from both using an inexpensive basic material and the simplified manufacturing procedures involved, requiring only the controlled deformation of a conventionally formed convolute tube prior to a final curing of the resins or adhesives between the plies.
Support posts formed in the above manner ideally have high stacking strength and an ability to provide for a lateral protecting and cushioning of the product. However, the structural integrity of the conventional posts when subjected to excess loading in the cross section direction has been packaged products are frequently subjected to transverse forces resulting from handling equipment or contact with adjacent items, which forces are normally accommodated by transverse strength of the posts. Should this transverse loading become excessive, the conventional post will be compressed in a manner which both greatly affects the vertical compressive strength of the post and gives rise to the potential for damage to the product itself.
The conventional post, as for example noted in U.S. Pat. Nos. 4,482,054, issued Nov. 13, 1984, and 4,483,444, issued Nov. 20, 1984, comprises a pair of spaced walls with one or more full length lateral indentations or beads extending transversely between the walls. These indentations include diverging sides, so configured as to inherently open and flatten relative to each other upon the subjecting of the post to a transverse compressive load with the post under extreme compression. The post ultimately assumes, at the area of compression, a flat cross section consisting of only two layers defined by the outer and inner walls. Such a flattening of the support post will not only affect the longitudinal compressive strength of the post in an obvious manner, but will also substantially eliminate any cushioning property of the post and expose the packaged product to direct damage by the handling equipment and/or by dynamic impact loading.
With regard to product damage, appliances and the like are strongest at the vertical corners thereof, and normally relatively weak and susceptible to impact damage to the paneling thereon inward of the corners. Thus, a support post flattened to a basic two layers as above described will not only have little or no cushioning properties, but will also tend to transfer any compressive forces to the vertical edge of the compressed post and to the relatively weaker area of the product remote from the corner.